review comments

Author: magicwerk

log4j-api/src/main/java/org/apache/logging/log4j/message/ParameterFormatter.java

@@ -679,7 +679,8 @@ private static void appendArray(final short[] a, final StringBuilder str) {
     /**
      * @see Arrays#toString(int[])
      */
-    private static void appendArray(final int[] a, final StringBuilder str) {
+    // package protected to allow access from ParameterFormatterBenchmark
+    static void appendArray(final int[] a, final StringBuilder str) {
         int len = a.length;
         if (len == 0) {
             str.append("[]");

log4j-perf-test/src/main/java/org/apache/logging/log4j/message/ParameterFormatterBenchmark.java

@@ -112,21 +112,7 @@ public int appendArrayToString(final ThreadState state) {
     public int appendArrayStringBuilder(final ThreadState state) {
         StringBuilder buffer = state.buffer;
         buffer.setLength(0);
-        appendArray(INT_ARRAY, buffer);
+        ParameterFormatter.appendArray(INT_ARRAY, buffer);
         return state.buffer.length();
     }
-
-    // Copied as method is static
-    private static void appendArray(final int[] a, final StringBuilder str) {
-        int len = a.length;
-        if (len == 0) {
-            str.append("[]");
-            return;
-        }
-        str.append('[').append(a[0]);
-        for (int i = 1; i < len; i++) {
-            str.append(", ").append(a[i]);
-        }
-        str.append(']');
-    }
 }

src/changelog/.2.x.x/3645_speedup_array_logging.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<entry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="https://logging.apache.org/xml/ns"
+       xsi:schemaLocation="https://logging.apache.org/xml/ns https://logging.apache.org/xml/ns/log4j-changelog-0.xsd"
+       type="fixed">
+  <issue id="3645" link="https://github.com/apache/logging-log4j2/pull/3645"/>
+  <description format="asciidoc">
+    Improve performance and avoid memory consumption if logging primitive arrays as parameters
+  </description>
+</entry>